Hong Kong should seek to reduce demand for energy by drafting new laws and charging more for electricity at peak hours, a Nobel laureate has urged.

Steven Chu yesterday offered some advice to Hong Kong on saving energy before crossing the border to give a talk on energy issues at Shantou University in Guangdong.

Dr Chu, a professor at the University of California, Berkeley, was one of three people who won a Nobel Prize in physics in 1997 for developing ways to cool and trap atoms with lasers. He is also a member of the Chinese Academy of Sciences focusing on energy issues.

Dr Chu is now involved in research into storing solar energy from deserts and biofuel from cropland.

He said the Academy of Sciences had just completed a study on global oil dependency, which is expected to be released in October. It will include plans to cope with energy problems, such as greenhouse gas emissions and climate change.

The study, which Dr Chu co-chaired, will first be unveiled in Beijing, a city that contributes a large amount of carbon emissions.

Dr Chu said Hong Kong could save energy in many ways.

First, he pointed to the light bulbs in a hotel conference room. 'Buildings can save a lot of money. Hong Kong should start with the lighting and outlaw these bulbs,' he said, adding that energy-efficient bulbs use up to 75 per cent less energy.

He said the government should follow California's example and pass regulations that require people to live more energy-efficient lives, such as by controlling energy use in residential and commercial buildings.

He said energy companies in California charged customers a higher price for electricity used at peak hours, because power companies were required to invest in more capacity to meet demand at peak times.

To monitor energy use during peak hours, and thereby save money, factories and homes in California were now installing meters that monitored the amount of electricity used in real time, he said.

'People will start washing their dishes and clothes at night because it is less expensive.'

The Hong Kong government also should try to get local businesses operating on the mainland to invest in energy-efficient facilities, he said, as hundreds of millions of people move from rural areas into the cities, creating more pollution.

The Lawrence Berkeley National Laboratory, headed by Dr Chu, was awarded US$500 million from the giant oil company British Petroleum this year to search for new sources of clean energy.